This invention concerns novel biomimetic hydrogel materials and methods for their preparation. In particular, the invention concerns hydrogels containing acrylamide-functionalized carbohydrate, sulfoxide, sulfide or sulfone copolymerized with hydrophilic or hydrophobic copolymerizing material, such as acrylamide, methacrylamide, acrylate, methacrylate or vinyl or their derivatives such as 2-hydroxyethyl methacrylate, and methods for their preparation. The invention also concerns the use of the new hydrogels for fabrication of soft contact lenses and biomedical implants. Additionally, the invention concerns novel acrylamide-functionalized carbohydrates, sulfoxide, sulfide and sulfone.
Hydrogel polymers have found widespread use in the biomedical materials industry as implant materials in both vascular and tissue environments. They are readily fabricated into a variety of morphologies and can exhibit a range of properties depending on their constituents. Their defining feature is the ability to absorb and hold water, a property which is dominated by the presence of hydrophilic groups in the bulk material.
Biological hydrogels serving various functions are known in nature. For example, during the process of bone growth collagen fibers form hydrogels upon which mineral nucleation takes place. The carbohydrate layer of the cell surface forms a hydrogel-like matrix that protects and hydrates the cell surface. The sophisticated structures of this nature fulfill various functions in complex biological processes.
By comparison, the hydrogel polymers that are manufactured for biomedical applications bear little functionality.
Polymers having pendant sugar moieties know as xe2x80x9cglycopolymersxe2x80x9d (Bioconj. Chem., 3:256 (1992) have attracted much interest in recent years, largely as scaffolds for the multivalent display of biologically important carbohydrate molecules. These glycopolymers have been used as potent inhibitors of viral-host cell attachment and leukocyte-endothelial cell adhesion (FEBS, 272:209 (1990); Can. J. Microbiol., 37:233 (1991); J. Am. Chem. Soc., 119:3161 (1997). Glycopolymers have also been explored as vehicles for targeted drug and gene delivery (J. Hepatology, 21:806 (1994), and as artificial substrates for cell adhesion (J. Cell Biol., 115:485 (1991). The suitability of glycopolymers as biocompatible implant materials has been relatively unexplored and is limited to a few examples described, for example, in Microbiol. Chem. Phys., 195:3597 (1994).
For polymers used as biocompatible implant materials, their properties, particularly the surface composition, are of great importance. Efforts include introducing biocompatible components into the bulk system and on their surface. Studies described, for example, in J. Colloid Interface Sci., 149:84 (1992) have shown that copolymers with a pendant glucose unit in the bulk or surfaces with covalently bound neutral polysaccharides demonstrate the reduction of platelet adhesion and protein adsorption.
The primary objective of this invention is thus to provide novel biomimetic, biocompatible hydrogel materials of modified surface having the high hydrophilicity, wettability and low protein adsorption suitable for use as biomedical implants.
All U.S. patents and patent applications cited and referred to herein are hereby incorporated by reference.
One aspect of the current invention is a hydrogel material prepared by copolymerization of hydrophilic or hydrophobic copolymerization material with acrylamide-functionalized carbohydrate monomers.
Another aspect of the current invention is a hydrogel material wherein the carbohydrate monomer is selected from the group consisting of N-methyl-N-xcex2-rhamnosyl acrylamide, N-[3-(2-N-ethyl propenamido)thiopropyl]-xcex2-N-xylosyl acetamide, N-acryloyl-N-methyl-D-glucamine, N-acryloyl-D-glucamine and N-acryloyl-N-(4-(3,6,9-trioxa)decyloxybenzyl)-D-glucamine.
Still another aspect of the current invention is an acrylamide-functionalized carbohydrate selected from the group consisting of N-methyl-N-xcex2-rhamnosyl acrylamide, N-[3-(2-N-ethyl propenamido)thiopropyl]-xcex2-N-xylosyl acetamide, N-acryloyl-N-methyl-D-glucamine, N-acryloyl-D-glucamine and N-acryloyl-N-(4-(3,6,9-trioxa)decyloxybenzyl)-D-glucamine.
Still another aspect of the current invention is a method for synthesis of hydrogel comprising an acrylamide-functionalized carbohydrate monomer.
Yet another aspect of the current invention is a hydrogel material prepared by copolymerization of copolymerization material with sulfoxide, sulfide or sulfone.
Still yet another aspect of the current invention is a method for preparation of sulfoxide, sulfide or sulfone containing hydrogels.
Still yet another aspect of the current invention is a hydrogel acrylamide containing carbohydrate, sulfoxide, sulfide or sulfone useful for production of improved soft contact lenses and other biomedical implants.
Still yet another aspect of the current invention is an acrylamide-functionalized sulfoxide, sulfide or sulfone.